Voltile Matter Of Petroleum Cone

Question 1

2. Procedure

Answer 1

•all VM analyses are performed in duplicate. Examine crucibles for cleanliness and examine kids for fit and verify no obstructions in hole of lid
•record cycle number along with date and time in record book
1. Weigh empty crucible and lid. Record weight. Do not tare scale after recording weight
2. Weigh ~1.000g of dried and finely ground come sample into crucible. Record weight of crucible, lid and sample above weight in step 1.
3. Subtract weight of empty crucible from weight of sample, crucible and lid and get sample weight. Repeat 1-3 for duplicate
4. Verify kids securely in crucible, place crucible into wire supports and use tool or sturdy metal rod to slide through both holes in wire supports and place in furnace. Once in furnace make certain they are centered and start timer for 7 minutes.
5. Using mirrors over furnaces, observe flame as it appears through hole in lids of crucibles. Note if record book if it is abnormal (flame is above lid and or soot is noticeable leaving through hole in lid) or normal
6. After 7 minutes remove wire supports holding crucibles and place in ring stand to cool. Allow to cool for 10 minutes. To ensure consistency of results, do not allow cooling period to extend beyond 15 minutest
7. Remove crucibles from wire support and reweigh crucibles,kids and remaining contents. Record weights

Question 2

3. Calculations and reporting of data

Answer 2

%VM = (mass loss of sample during heating)/(mass of sample) x 100

•report percent of volatile matter to nearest 0.01%

Repeatability - the difference between successive results by same operator using same apparatus under constant operating conditions in identical test materials. Limits may be determined by the following:
Repeatability = 0.20
Reproducibility - difference between two single and independent results obtained by different operators working in different laboratories in identical test materials. Reproducibility limits may be determined by:
Reproducibility = 0.27 + 0.27(x)
Where x is average of two results jn weight percent

•if VCM exceeds 11.50 limit it is necessary to call Decoker at 5214 for resample

Question 3

4. Quality control standards

Answer 3

• VCM standard run Monday, Wednesday, and Friday. Results should be recorded in QC book, QC software and or plotted by chemist over lab
• thermocouples in electric furnaces are checked when duplicate results from identical test materials (repeatability) exceeds 0.8 times average of two test results and other possible problems have been ruled out.

Question 4

5. Troubleshoot

Answer 4

• verify crucibles clean and lid fits snug
• brush wire supports before putting crucibles in paled
• clean mirrors for unobstructed viewing
• after initial burning of volatile material, check that kid is still in place. If necessary, raise wire support to top of furnace and carefully reposition the kid to reduce admission of air into sample. Immediately lower sample into furnace
• check temperature of furnaces
• check length of wire supports. Bottom of crucible should be 2-3mm from top of thermocouple. Extremely importance since required temp of oven is 950+/-20*C jn crucible dependent on positioning of crucible. Closer crucible is to thermocouple, more precise control of temperature.
• moisture can create erroneously high results. Make sure coarse ground coke was dried thoroughly and stirred at regular intervals for even drying.
• verify accuracy of fine grinder. Particle size can affect volatile matter. Larger particle size, lower volatile matter. A sieve analysis can help by identifying if adjustments need to be made to fine grinder to ensure that 100% of finely ground coke oases through 60 mesh sieve and 40-50% is retained in 120 mesh sieve.

Question 5

1. Purpose

Answer 5

Determines amount of volatile matter (VCM) in sample of petroleum coke. Volatile matter can be used as indicator of yield on carbonization process and to determine its burning characteristics